TY - JOUR
T1 - Microstructure and mechanical properties of Ti-2Al alloyed with Mo formed in laser additive manufacture
AU - Zhang, Fengying
AU - Yang, Meng
AU - Clare, Adam T.
AU - Lin, Xin
AU - Tan, Hua
AU - Chen, Yongnan
N1 - Publisher Copyright:
© 2017
PY - 2017
Y1 - 2017
N2 - A series of Ti-2Al-yMo (y = 2,5,7,9,12) alloy samples were produced from blended elemental Ti, Al and Mo powders using the laser solid forming technology. The influence of the β stabilizer Mo on the morphology of the grains, the size and the distribution of the α laths, the Vickers hardness and the tensile properties of Ti-2Al-yMo alloys were explored under designated laser processing parameters. It was found that the microstructure in Ti-2Al-5Mo, Ti-2Al-7Mo, Ti-2Al-9Mo, and Ti-2Al-12Mo deposited layers were composed of irregular columnar grains that grow epitaxially, with some small equiaxed grains in the upper region, while that of the Ti-2Al-2Mo alloy was composed of large columnar grains. The grain size decreased, while the thickness of equiaxed grains layer increased with increasing Mo content. This indicates a tendency towards columnar-to-equiaxed transition with increasing Mo. The dominant β grains form a basketweave microstructure composed of primary α laths, secondary α laths and retained β phase. It was also observed that with increasing Mo content, both the size of primary α laths and secondary α laths decreased significantly, while the number of secondary α laths increased sharply, and the Ti-2Al-12Mo is also constituted of α phase and β phase. The Young's modulus of Ti-2Al-7Mo, Ti-2Al-9Mo, and Ti-2Al-12Mo were basically the same within experimental error. Tensile testing of the specimens showed that Ti-2Al-7Mo exhibits a good combination of strength and elongation to failure. As a result, this material can be considered suitable as a viable feedstock for laser additive manufacturing.
AB - A series of Ti-2Al-yMo (y = 2,5,7,9,12) alloy samples were produced from blended elemental Ti, Al and Mo powders using the laser solid forming technology. The influence of the β stabilizer Mo on the morphology of the grains, the size and the distribution of the α laths, the Vickers hardness and the tensile properties of Ti-2Al-yMo alloys were explored under designated laser processing parameters. It was found that the microstructure in Ti-2Al-5Mo, Ti-2Al-7Mo, Ti-2Al-9Mo, and Ti-2Al-12Mo deposited layers were composed of irregular columnar grains that grow epitaxially, with some small equiaxed grains in the upper region, while that of the Ti-2Al-2Mo alloy was composed of large columnar grains. The grain size decreased, while the thickness of equiaxed grains layer increased with increasing Mo content. This indicates a tendency towards columnar-to-equiaxed transition with increasing Mo. The dominant β grains form a basketweave microstructure composed of primary α laths, secondary α laths and retained β phase. It was also observed that with increasing Mo content, both the size of primary α laths and secondary α laths decreased significantly, while the number of secondary α laths increased sharply, and the Ti-2Al-12Mo is also constituted of α phase and β phase. The Young's modulus of Ti-2Al-7Mo, Ti-2Al-9Mo, and Ti-2Al-12Mo were basically the same within experimental error. Tensile testing of the specimens showed that Ti-2Al-7Mo exhibits a good combination of strength and elongation to failure. As a result, this material can be considered suitable as a viable feedstock for laser additive manufacturing.
KW - Direct energy deposition
KW - Laser additive manufacturing
KW - Laser solid forming
KW - Mechanical properties
KW - Microstructure
KW - Titanium alloys
UR - http://www.scopus.com/inward/record.url?scp=85028326577&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2017.07.324
DO - 10.1016/j.jallcom.2017.07.324
M3 - 文章
AN - SCOPUS:85028326577
SN - 0925-8388
VL - 727
SP - 821
EP - 831
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
ER -